Answer:
The magnitude of the net force is 5430N
Explanation:
I suggest to define the axes as aligned to the axis of the plane. This will require you to decompose only one vector, namely the Weight. We need two components of the W force: one in horizontal direction of the plane, the other perpendicular to it. Through a simple triangle argument you will se that the plane-horizontal component of W is
acting in the direction of the Drag, and the plane-perpendicular component is:
with negative sign since it counteracts the Lift.
So the components of the netforce F are:
The magnitude of the net force is: